1. Field of the Invention
The present invention relates to an image filing method, and more particularly to a data structure of retrieval information, a formation of the retrieval information and a graphical user interface.
2. Description of the Related Arts
In general, in an image data base, when image data are registered, a specific feature amount of each image is automatically calculated, and by registering its calculation result as retrieval information, the retrieval by using the feature amount of each image can be carried out.
On the basis of such a viewpoint, as shown in FIG. 1, a conventional image filing system has been proposed, as disclosed in Japanese patent Laid-Open No. Sho 63-254856. In FIG. 1, the image filing system includes a CPU 1 for controlling the whole system, an image input part part 2 for inputting multi-valued images from the outside, an image storage part 3 for storing the multi-valued images, an image retrieval part 4 for retrieving the multi-valued images stored in the image storage part 3 by using their retrieval information, an operational terminal part 5 for inputting operational instructions such as registration and retrieval instructions to the image retrieval part 4, an image display part 6 for displaying the multi-valued image input from the image input part part 2 or the reproduced multi-valued image retrieved from the image storage part 3 by the image retrieval part 4, a spectrum distribution calculation part 7 for calculating a spectrum distribution, that is, one item of statistical information of the multi-valued images input from the image input part 2, and a density distribution calculation part 8 for calculating a density distribution, that is, another item of statistical information of the multi-valued images input from the image input part part 2.
Next, the operation of this image filing system will be described. The operation of the image filing can be roughly divided into two operations such as a registration operation and a retrieval operation.
Firstly, at the registration time, a user inputs a suitable key word as retrieval information for an image from the operational terminal part 5. Also, a spectrum distribution of a multi-valued image to be registered is calculated in the spectrum distribution calculation part 7. Further, a density distribution of the multi-valued image to be registered is calculated in the density distribution calculation part 8. Then, from the obtained spectrum and density distributions, an expected value of the spectrum distribution as a measure of sharpness and an expected value of the density distribution as a measure of brightness are calculated, and the calculated values are registered together with other retrieval information.
Secondly, the operation at the retrieval time will be described in connection with FIG. 2. In an example shown in FIG. 2, a name having a common character "WEST" in its head and an unlimited symbol "*" in its latter part as a key word of names is input from the operational terminal part 5. Then, by a retrieval using this key word in the image retrieval part 4, a list of relevant images such as A, B, C and D is displayed and the firstly retrieved image A is displayed in the image display part 6. Next, when an instruction for a brighter and sharper image on the basis of the image A displayed in the image display part 6 is input from the operational terminal part 5, an expected value f1 of the spectrum distribution and an expected value g1 of the density distribution, that is, the retrieval information of the image A are compared with those of the other images, and the image D having a larger expected value f2 of the spectrum distribution and a larger expected value g2 of the density distribution is retrieved and displayed in the image display part 6.
In the conventional image filing system, as described above, after performing the keyword retrieval, an auxiliary secondary retrieval using the feature amounts such as the expected values f1 and g1 of the spectrum and density distributions is executed. Hence, the keyword input operations are required at the image registration and retrieval times, and it takes a lot of time and labor. In particular, the keyword registration operation at the image registration time is so important that how to give the key words may determine the performance of the whole image filing system. That is, it is necessary to allot key words which are readily identifiable with the images to be registered by an operator at the image registration time. Further, since there are different reasons between individuals for giving the key words, a registration error and a retrieval error is apt to occur, and as a whole, the registration operation and the retrieval operation become complicated.
Further, in a color image, when the retrieval is performed by using the measures such as the sharpness and the brightness as the feature amounts of the image, an image which does not sufficiently represent these feature of the color image can not be retrieved.